Sandblasting is a process in which an abrasive, such as sand, is discharged from a sandblasting gun or nozzle against a surface to be cleaned in preparation for painting or some other process. A supply of sand or other abrasive is carried in a “pot,” and upon activation of the system, an operator allows the sand to travel from the pot and through a hose to be discharged through the nozzle.
The supply pot of the abrasive and its operator are most often at a location remote from, and sometimes out of the sight of, the blasting site. For example, if a bridge is being sandblasted, the pot and its operator will be on the ground, remote from the bridge, and often the sandblasting person will be out of the sight of the pot operator, possibly hundreds of feet away. Oftentimes during the blasting operation, there is a need to adjust the amount of sand flowing through the hose. The communication of this need from the blaster to the pot operator is a significant problem. Even if the blaster and the operator were within normal earshot, the noisy environment of the sandblasting operation makes it difficult, if not impossible, for these two people to orally communicate. Hand signals are not a solution because, as discussed above, the blaster may be out of the sight of the pot operator, and even if the two had visual communication, due to other duties, the pot operator cannot focus his attention constantly on the blaster.
Most often, the blaster uses some kind of code to attempt to communicate with the pot operator. That is, if the blaster needs a larger flow of abrasive, he may quickly turn the nozzle on and off, for example, three times, and if a smaller flow of abrasive is needed, he may quickly turn the nozzle on and off two times. If the pot operator observes this activity, he will then be able to adjust the abrasive supply accordingly. However, this not only requires that the pot operator be nearby the pot, but it also requires that he has his full attention on the pot at all times. Even then, in view of the noisy environment, the pot operator may not recognize the signal being transmitted.
Thus, the need exists for a system which will allow the blasting nozzle operator to communicate with the pot operator not only the need for action, but also the type of action to be taken.